Electromagnetic solenoid type flow control valves are generally known in the art. Conventional solenoid actuated valve devices have been proposed which use a linear motor of the movable coil type and a valve means. The linear motor includes a core, a bobbin slidably mounted on the core, a solenoid coil wound on the bobbin, permanent magnets with the magnetic flux of each magnet intersecting the winding of the solenoid coil at right angles and a yoke or body forming a magnetic circuit with the core. The valve means in general includes a sliding valve member which is slidable with the bobbin on the core in response to the electric current going through the solenoid coil to thereby proportionally control openings formed in the core between an inlet port and an outlet port.
In such conventional solenoid actuated valve devices, when the solenoid coil receives no electric current, the sliding valve member is always biased by means of a pair of springs in a direction so that the sliding valve member will completely open or completely close the openings to thereby interrupt or fully establish the fluid communication between the inlet and outlet ports. Therefore, in order to cause the sliding valve to move to the full extent in the opposite direction from which it is normally biased, a large magnetic or exciting force must be generated by the application of electric current to the solenoid coil.
In a known electromagnetic solenoid type flow control valve, the valve includes a valve member slidable along the outer surface of the core to cover the valve ports. When the solenoid coil is energized, the bobbin and the valve member are displaced against the influence of the springs to open the valve ports and to cover the valve ports.
In a known solenoid actuated valve device, a core is supported by a body and a cover member for axial movement relative thereto. While the solenoid coil receives no electric current, the bobbin, having a valve portion, is maintained in its original position, therefore the air at the inlet port is transmitted to the outlet port by means of the first opening. When the solenoid coil receives a positive electric current, the bobbin is moved to the right in proportion to the strength of the electric current whereby the valve portion proportionally opens the second opening means to thereby increase the fluid communication between the inlet and outlet ports. When the solenoid coil receives a negative electric current, the bobbin is moved to the left in proportion to the strength of the electric current whereby the valve portion proportionally closes the first opening to thereby restrict the fluid communication between the inlet and outlet ports, respectively.
A known slide valve is driven along a hollow core by a linear motor to control the degree of communication between an inlet and an outlet port through the hollow interior of the iron core. A bobbin-type slide valve is slidably disposed on the iron core and fixedly secured to a bobbin holder. The bobbin holder is biased by means of two springs. An electromagnetic coil is wound on the slide valve through the intermediary of the bobbin holder and a pair of permanent magnets are provided within the valve assembly and arranged in such a manner that the magnet flux produced thereby passes through the windings of the electromagnetic coil at a right angle.
An engine mixture control system is known for controlling primary and secondary air-fuel mixtures. Around the outer cylindrical surface of the support pipe there is fitted a slide sleeve of a generally hollow cylindrical form. The inner cylindrical surface of the slide sleeve closely conforms to the outer cylindrical surface of the support pipe, so that as the slide sleeve moves upwards and downwards with respect to the support pipe, the upper edge of the slide sleeve moves across the valve port and thus regulates the effective open area of the valve port.
In a known manually controllable automobile governor, a valve element is mounted on a body member with an opening extending through the body portion of the valve element. The body member closely fits within the passage in slidable relation therein to substantially prevent liquid flow between the passage wall and the body portion. An opening extends transversely through the valve element and is of a size sufficient to be able to carry a flow of liquid fuel equal to the flow capabilities of the opening in the valve element and the inlet passage of the body member. A compression spring engages the end of the valve element to normally close the transverse opening of the valve member. A coil or solenoid is wound circumferentially around and engaged with the body member. When the solenoid is energized, the valve element moves in opposition to the spring thereby opening the passage to allow greater fuel flow than is possible through the restricted opening.
While each of these previously known valve configurations appears to be capable of adequately performing its intended function, the configurations disclosed are overly complex and difficult to manufacture in a cost-effective manner. It is therefore desirable in the present invention to provide a simplified electromagnetically driven flow control valve assembly that is easier to manufacture in a cost-effective manner. It is further desirable to provide a simple construction valve to check flow when the valve assembly is in the closed condition.